This invention generally relates to a method of detecting air filter condition for heating, ventilating, and air conditioning systems.
Typically, an air handling system includes a filter to block and collect airborne debris. The air filter becomes blocked with usage and must be changed periodically. A blocked air filter can increase power consumption, reduce cooling and heating capacity, and cause premature component failure.
Inspection of an air filter for a large commercial air handling system can require partial dismantling of portions of the system. Dismantling the system is costly, time consuming and therefore not desirable. It is for this reason that filter detection systems have been developed.
Current filter detection devices utilize sensors installed within the air handling system that directly detect changes in airflow, temperature or other measured parameters. Further, other known devices utilize optical sensors to visually recognize a clogged filter.
Disadvantageously, prior art filter detection systems require additional sensors installed within the air handling system. The additional sensors require additional controls that increase cost and complexity. Other systems require modification to the filter for mounting of a sensor within the filter. The use of additional sensors may not be effective for systems that utilize a variable speed blower or fan. Further, known detection systems only detect, instead of predict, a clogged condition. It is preferable to replace air filters according to a predictable schedule that coincides with other periodic maintenance.
Accordingly, it is desirable to develop a system for detecting and predicting air filter condition that utilizes information presently available within the system without additional sensors that is effective for variable blower systems.